scholarly journals Effects of Concentration and Surface Pressure on MBP Interaction with Cholesterol in Langmuir Films

Scanning ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Lei Zhang ◽  
Changchun Hao ◽  
Guoqing Xu ◽  
Runguang Sun
Keyword(s):  
Surface Morphology ◽  
Surface Pressure ◽  
Protein Concentration ◽  
Molecular Mechanisms ◽  
Convincing Evidence ◽  
Langmuir Films ◽  
Domain Formation ◽  
Molecular Area ◽  
Lateral Membrane ◽  
Lateral Organization

Predicting the mechanism of MBP binding to cholesterol is meaningful in understanding how MBP participate in lateral membrane organization. The interaction of MBP with cholesterol monolayer was investigated at three surface pressures on 10 mM Tris-HCl buffer with the different concentrations of MBP. The results show that π-A isotherms shift to larger molecular area at all pressures. By means of analyzing π-T curves, a surface pressure increase was obtained. Results indicated that the greater the protein concentration in the subphase, the larger the increase of surface pressure. In addition, changes in monolayer surface morphology and domain formation were performed by AFM. These results provide more direct and convincing evidence for the MBP interaction with cholesterol. The MBP-cholesterol interaction suggests a significant concentrations and surface pressure dependence and is probably governed by hydrogen bonds. The date presented could help to understand at least one of the molecular mechanisms through which MBP affects lateral organization of the cholesterol membrane.

scholarly journals Langmuir-Blodgett Films of Supported Polyester Dendrimers

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Rocío Redón ◽  
M. Pilar Carreón-Castro ◽  
F. J. Mendoza-Martínez
Keyword(s):  
Surface Pressure ◽  
Dendritic Structure ◽  
The Self ◽  
Langmuir Films ◽  
Interfacial Behavior ◽  
Brewster Angle Microscopy ◽  
Molecular Area ◽  
Langmuir Blodgett ◽  
Self Assembling ◽  
Langmuir Blodgett Films

Amphiphiles with a dendritic structure are attractive materials as they combine the features of dendrimers with the self-assembling properties and interfacial behavior of water-air affinities. We have synthesized three generations of polyester dendrimers and studied their interfacial properties on the Langmuir films. The behavior obtained was, as a rule, the lowest generation dendrimers behaving like traditional amphiphiles and the larger molecules presenting complicated isotherms. The Langmuir films of these compounds have been characterized by their surface pressure versus molecular area (π/A) and Brewster angle microscopy (BAM) observations.

Modelling of Molecular Mechanisms of Membrane Domain Formation during the Oxidative Stress: Effect of Palmitoyl-oxovaleroyl-phosphatidylcholine

2021 ◽  
Author(s):  
Vesela Yordanova ◽  
Galya Staneva ◽  
Miglena Angelova ◽  
Victoria Vitkova ◽  
Aneliya Kostadinova ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Molecular Mechanisms ◽  
Stress Effect ◽  
Domain Formation ◽  
Membrane Domain

scholarly journals Functional Proteomic Analysis of Human Nucleolus

2002 ◽  
Vol 13 (11) ◽  
pp. 4100-4109 ◽  
Author(s):  
Alexander Scherl ◽  
Yohann Couté ◽  
Catherine Déon ◽  
Aleth Callé ◽  
Karine Kindbeiter ◽  
...  
Keyword(s):  
Proteomic Analysis ◽  
Ribosome Biogenesis ◽  
Molecular Mechanisms ◽  
Convincing Evidence ◽  
Biological Processes ◽  
Functional Classification ◽  
Control Of Gene Expression ◽  
Nucleolar Proteins ◽  
Nuclear Domain

The notion of a “plurifunctional” nucleolus is now well established. However, molecular mechanisms underlying the biological processes occurring within this nuclear domain remain only partially understood. As a first step in elucidating these mechanisms we have carried out a proteomic analysis to draw up a list of proteins present within nucleoli of HeLa cells. This analysis allowed the identification of 213 different nucleolar proteins. This catalog complements that of the 271 proteins obtained recently by others, giving a total of ∼350 different nucleolar proteins. Functional classification of these proteins allowed outlining several biological processes taking place within nucleoli. Bioinformatic analyses permitted the assignment of hypothetical functions for 43 proteins for which no functional information is available. Notably, a role in ribosome biogenesis was proposed for 31 proteins. More generally, this functional classification reinforces the plurifunctional nature of nucleoli and provides convincing evidence that nucleoli may play a central role in the control of gene expression. Finally, this analysis supports the recent demonstration of a coupling of transcription and translation in higher eukaryotes.

Surface pressure-induced isothermal 2D- to 3D-transitions in Langmuir films of poly(ε-caprolactone)s and oligo(ε-caprolactone) based polyesterurethanes

2015 ◽  
Vol 26 (12) ◽  
pp. 1411-1420 ◽  
Author(s):  
Anne-Christin Schöne ◽  
Karl Kratz ◽  
Burkhard Schulz ◽  
Jürgen Reiche ◽  
Svetlana Santer ◽  
...  
Keyword(s):  
Surface Pressure ◽  
Langmuir Films ◽  
2D To 3D

scholarly journals Humidity-dependent compression-induced glass transition of the air–water interfacial Langmuir films of poly(d,l-lactic acid-ran-glycolic acid) (PLGA)

Soft Matter ◽  
2015 ◽  
Vol 11 (28) ◽  
pp. 5666-5677 ◽  
Author(s):  
Hyun Chang Kim ◽  
Hoyoung Lee ◽  
Hyunjung Jung ◽  
Yun Hwa Choi ◽  
Mati Meron ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Glass Transition ◽  
Surface Pressure ◽  
Glycolic Acid ◽  
High Surface ◽  
Polymer Concentration ◽  
Langmuir Films ◽  
Exponential Increase ◽  
Constant Rate ◽  
Compression Isotherms

Constant rate compression isotherms of the air–water interfacial Langmuir PLGA films show a distinct feature of an exponential increase in surface pressure in the high surface polymer concentration regime.

AMPK agonist AICAR delays the initial decline in lifetime-apex V̇o2 peak, while voluntary wheel running fails to delay its initial decline in female rats

2016 ◽  
Vol 48 (2) ◽  
pp. 101-115 ◽  
Author(s):  
Ryan G. Toedebusch ◽  
Gregory N. Ruegsegger ◽  
Joshua F. Braselton ◽  
Alexander J. Heese ◽  
John C. Hofheins ◽  
...  
Keyword(s):  
Protein Concentration ◽  
Molecular Mechanisms ◽  
Outcome Measure ◽  
Wheel Running ◽  
Female Rats ◽  
Peak Oxygen Consumption ◽  
Chronological Age ◽  
Primary Hypothesis ◽  
Running Wheels ◽  
Voluntary Wheel

There has never been an outcome measure for human health more important than peak oxygen consumption (V̇o2 peak), yet little is known regarding the molecular triggers for its lifetime decline with aging. We examined the ability of physical activity or 5 wk of 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR) administration to delay the initial aging-induced decline in lifetime-apex V̇o2 peak and potential underlying molecular mechanisms. Experiment 1 consisted of female rats with (RUN) and without (NO RUN) running wheels, while experiment 2 consisted of female nonrunning rats getting the AMPK agonist AICAR (0.5 mg/g/day) subcutaneously for 5 wk beginning at 17 wk of age. All rats underwent frequent, weekly or biweekly V̇o2 peak tests beginning at 10 wk of age. In experiment 1, lifetime-apex V̇o2 peak occurred at 19 wk of age in both RUN and NO RUN and decreased thereafter. V̇o2 peak measured across experiment 1 was ∼25% higher in RUN than in NO RUN. In experiment 2, AICAR delayed the chronological age observed in experiment 1 by 1 wk, from 19 wk to 20 wk of age. RUN and NO RUN showed different skeletal muscle transcriptomic profiles both pre- and postapex. Additionally, growth and development pathways are differentially regulated between RUN and NO RUN. Angiomotin mRNA was downregulated postapex in RUN and NO RUN. Furthermore, strong significant correlations to V̇o2 peak and trends for decreased protein concentration supports angiomotin's potential importance in our model. Contrary to our primary hypothesis, wheel running was not sufficient to delay the chronological age of lifetime-apex V̇o2 peak decline, whereas AICAR delayed it 1 wk.

scholarly journals Medial-lateral Organization of the Orbitofrontal Cortex

2014 ◽  
Vol 26 (7) ◽  
pp. 1347-1362 ◽  
Author(s):  
Erin L. Rich ◽  
Jonathan D. Wallis
Keyword(s):  
Secondary Reinforcement ◽  
Convincing Evidence ◽  
Behavioral Task ◽  
Lateral Extent ◽  
External Stimuli ◽  
Orbital Region ◽  
Different Sources ◽  
Lateral Organization ◽  
Shed Light ◽  
Human Neuroimaging

Emerging evidence suggests that specific cognitive functions localize to different subregions of OFC, but the nature of these functional distinctions remains unclear. One prominent theory, derived from human neuroimaging, proposes that different stimulus valences are processed in separate orbital regions, with medial and lateral OFC processing positive and negative stimuli, respectively. Thus far, neurophysiology data have not supported this theory. We attempted to reconcile these accounts by recording neural activity from the full medial-lateral extent of the orbital surface in monkeys receiving rewards and punishments via gain or loss of secondary reinforcement. We found no convincing evidence for valence selectivity in any orbital region. Instead, we report differences between neurons in central OFC and those on the inferior-lateral orbital convexity, in that they encoded different sources of value information provided by the behavioral task. Neurons in inferior convexity encoded the value of external stimuli, whereas those in OFC encoded value information derived from the structure of the behavioral task. We interpret these results in light of recent theories of OFC function and propose that these distinctions, not valence selectivity, may shed light on a fundamental organizing principle for value processing in orbital cortex.

Properties of Calix4-Lead(Pb) Films Using Langmuir-Blodgett (LB) Technique as an Application of Ion Sensor

2014 ◽  
Vol 895 ◽  
pp. 8-11 ◽  
Author(s):  
Noor Azyyati Azahari ◽  
Faridah Lisa Supian ◽  
Tim H. Richardson ◽  
Syed Abdul Malik
Keyword(s):  
Dipole Moments ◽  
Langmuir Films ◽  
Lead Chloride ◽  
Chloride Salt ◽  
Molecular Area ◽  
Langmuir Blodgett ◽  
Sensor Devices ◽  
Pressure Area ◽  
Nanometric Film ◽  
Potential Area

Calixarenes are promising compounds to be used as ionophores and for molecular recognition. Their ability to form Langmuir and Langmuir-Blodgett (LB) films is of great interest in order to obtain small sensor devices which incorporate an active nanometric film. Calix[4]arene (Calix4) has been used in this work and its ability to form Langmuir films has been shown. Calix4 forms monolayers but at higher compressions tends to form multilayers. The presence of ions in the subphase, as lead chloride salt solutions, leads to some changes in the surface pressure-area (П-A) isotherms and surface potential-area (ΔV-A) isotherms. The effective dipole moments (μ) of the calixarene molecules in the uncomplexed and complexed states has been calculated from the ΔV values by using Helmholtz equation. Some characteristics of the films and mean molecular area have been deduced from the isotherms graph.

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